Received the update yesterday, but now my alarm won't work and LED indicator isn't working either. Is there a fix/setting to this, or a way to undo the update to get back to the old state?
If you havent already done so before the update, back up your information such as pics, music files etc...go in your back up and restore menu in settings and uncheck app restore and app info, then master reset your phone to factory state. You cannot go back to the previous state, but you can start fresh with a reset phone which will put things back to default.
Just to confirm I should uncheck those boxes? Won't I then gave to manually
add back all apps?
Yes, you will have to manually add the apps back from the play store app, which you can do in batch mode. The point is, is that your old apps have to be converted from one format to another and it is better to have a clean slate than to change a copy. Old apps leave fragments and this might corrupt installation of new OS.